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Nit: fix locking of p->p_state in procdesc_close().

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According to <sys/proc.h>, this field needs to be locked with either the
p_mtx or the p_slock. In this case the damage was quite small. Instead
of being reaped, the process would just be reparented to init, so it
could be reaped from there.
This commit is contained in:
Ed Schouten 2014-04-06 20:00:42 +00:00
parent 99bccc04fc
commit a90feb39a2
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=264200
1 changed files with 32 additions and 30 deletions
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62
sys/kern/sys_procdesc.c
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@ -364,39 +364,41 @@ procdesc_close(struct file *fp, struct thread *td)
* collected and procdesc_reap() was already called.
*/
sx_xunlock(&proctree_lock);
} else if (p->p_state == PRS_ZOMBIE) {
/*
* If the process is already dead and just awaiting reaping,
* do that now. This will release the process's reference to
* the process descriptor when it calls back into
* procdesc_reap().
*/
PROC_LOCK(p);
PROC_SLOCK(p);
proc_reap(curthread, p, NULL, 0);
} else {
/*
* If the process is not yet dead, we need to kill it, but we
* can't wait around synchronously for it to go away, as that
* path leads to madness (and deadlocks). First, detach the
* process from its descriptor so that its exit status will
* be reported normally.
*/
PROC_LOCK(p);
pd->pd_proc = NULL;
p->p_procdesc = NULL;
procdesc_free(pd);
if (p->p_state == PRS_ZOMBIE) {
/*
* If the process is already dead and just awaiting
* reaping, do that now. This will release the
* process's reference to the process descriptor when it
* calls back into procdesc_reap().
*/
PROC_SLOCK(p);
proc_reap(curthread, p, NULL, 0);
} else {
/*
* If the process is not yet dead, we need to kill it,
* but we can't wait around synchronously for it to go
* away, as that path leads to madness (and deadlocks).
* First, detach the process from its descriptor so that
* its exit status will be reported normally.
*/
pd->pd_proc = NULL;
p->p_procdesc = NULL;
procdesc_free(pd);
/*
* Next, reparent it to init(8) so that there's someone to
* pick up the pieces; finally, terminate with prejudice.
*/
p->p_sigparent = SIGCHLD;
proc_reparent(p, initproc);
if ((pd->pd_flags & PDF_DAEMON) == 0)
kern_psignal(p, SIGKILL);
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
/*
* Next, reparent it to init(8) so that there's someone
* to pick up the pieces; finally, terminate with
* prejudice.
*/
p->p_sigparent = SIGCHLD;
proc_reparent(p, initproc);
if ((pd->pd_flags & PDF_DAEMON) == 0)
kern_psignal(p, SIGKILL);
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
}
}
/*